General information for homeowners, not legal, engineering or insurance advice. Permit and historic district rules vary; check with the City of Columbus Department of Building and Zoning Services or your suburb’s building department before major roof work.
Slate is one of the longest-lasting roofing materials there is. Good slate can stay on a roof for generations, while the nails, flashing and gutters around it wear out much sooner. That’s why most slate roofs that “need replacing” really need repair. Here’s how to tell the difference.
Why most slate roofs can be repaired
On many older slate roofs, the stone itself is still solid. What fails are the parts around it: rusted nails let slates slip, thin metal valleys rust through, and chimney flashing cracks. Replacing those parts, and swapping out broken slates, keeps the roof working without throwing away good stone.
Signs repair is the right call
- Only some slates are cracked, slipped or missing
- Leaks are around the chimney, valleys or other flashed areas
- The slates you can see are hard, flat and not flaking
- Most problems trace back to one storm, a fallen branch or foot traffic
Signs the roof may be near the end
- Many slates are soft, flaking, crumbling or turning powdery
- Slates are breaking all over the roof, not just in one area
- Broken slates keep showing up no matter how many are fixed
- The wood under large areas of the roof has rotted
Even then, some roofs can be stripped and re-laid with the best of the old slate plus matching replacement slate. Ask about it.
Questions to ask before a tear-off
- How much of the slate itself is failing, and how did you check?
- Could the roof be repaired or restored instead? What would that cost?
- What is the real source of the leak?
- If we replace, what would go on instead, and how long would it last?
If someone recommends tearing off a slate roof, get the reasons in writing and get a second opinion from a roofer who works on slate regularly.
Historic homes in Columbus
In historic districts like German Village, Victorian Village, Italian Village and parts of Olde Towne East, changes to a roof’s look or material can need approval before work starts. Repairing slate with matching slate usually keeps things simple. Check with the City of Columbus or your district commission before you change materials.
Next steps
Start with an inspection if you’re unsure, or go straight toslate roof repair or restoration and leak repair. Every request gets a free written estimate.